Radio station for mobile communication systems and method for the selection of a transmission means

Abstract

In a radio station for mobile communication systems, the reception branches of at least two antenna units having different polarization are monitored in order to acquire statements about the polarization direction of the incident wave. Corresponding to the polarization direction of the incident wave, an adaptive fashioning of the radiation characteristic ensues, this fashioning the polarization direction of the emitted wave according to the weighting of the reception signals of the reception branches for the same communication connection. The connection from a base station to a mobile station in a mobile communication system therefore can be improved with an inventive radio station.

We claim as our invention: 
     
       1. A radio station for mobile communication systems, comprising: at least two antenna units with different polarization, each of the at least two antenna units being connected to respective duplexers for the separation of transmission and reception branches;   at least two channel separation units, each of the at least two channel separation units being connected to one of the duplexers for each reception branch;   at least two channel aggregation units, each of the at least two channel aggregation units being connected to one of the duplexers for each transmission branch;   a control unit for the transmission-branch control of transmission signals onto the antenna units according to a weighting procedure which correlates the transmission signals with reception signals of the reception branches;   means for level measurement of the reception signals received by the antenna units; and   means for determining the polarization direction of the reception signals from the level measurement, whereby the control unit operates to weight the transmission signals for the transmission branches according to the polarization of an incident wave of the reception signals.   
     
     
       2. A radio station as claimed in claim 1, further comprising: transmission signals of the two antenna units which are cross-polarized relative to one another.   
     
     
       3. A radio station as claimed in claim 1, further comprising: transmission signals of the two antenna units which are linearly cross-polarized relative to one another.   
     
     
       4. A radio station as claimed in claim 1, further comprising: transmission signals of the two antenna units which are oppositely circular cross-polarized relative to one another.   
     
     
       5. A radio station as claimed in claim 1, further comprising: means for determining quality criteria for the reception signals of the reception paths having different polarization of the antenna units; and   means for selecting a reception path on the basis of the quality criteria whereby the control unit switches the transmission signals onto the selected antenna unit.   
     
     
       6. A radio station as claimed in claim 1, further comprising: means for determining quality criteria for the reception signals of the reception paths having different polarization of the antenna units; and   means for selecting a reception path on the basis of the quality criteria, whereby the control unit hands-over the transmission path to a transmission means connected to an antenna unit receiving better reception signal according to the quality criteria.   
     
     
       7. A radio station as claimed in claim 5, whereby the quality criterion is defined on the basis of a bit error rate. 
     
     
       8. A radio station as claimed in claim 5, whereby the quality criterion is defined on the basis of a signal level. 
     
     
       9. A radio station as claimed in claim 5, whereby the quality criterion is defined on the basis of a signal-to-noise ratio. 
     
     
       10. A radio station as claimed in claim 5, whereby the quality criterion is defined on the basis of the ratio of carrier signal-to-noise signal. 
     
     
       11. A method for selecting a transmission means in a radio station as claimed in claim 6, comprising the steps of: supplying transmission signals of a transmission means to a permanently allocated antenna means;   determining quality measured values from reception signals of various reception branches over a measuring period;   comparing the quality measured values of the reception branches; and   handing-over a transmission path to the transmission means corresponding to the better reception branch if the quality measured value of this reception branch lies above that of a reception branch corresponding to a previously selected transmission branch.   
     
     
       12. A method as claimed in claim 11, whereby the quality measured values are level measured values and the step of handing-over is instituted if a difference between the level measured values exceeds a prescribable limit value. 
     
     
       13. A method as claimed in claim 11, whereby the step of handing-over is instituted only given the repeated presence of a higher level measured value in the reception path not corresponding to the selected transmission path. 
     
     
       14. A method as claimed in claim 11, whereby a subsequent step of handing-over is inhibited for a prescribable time span.